Apparatus for treating textile filaments



United States Patent 3,172,780 APPARATUS FOR TREATING TEXTILE FILAMENTSTibor Csok, Camden, S.C., and Thurman V. Williams, Jr., Wilmington,Del., and Thomas D. Williamson, Lugolf, S.C., assignors to El. du Pontde Nemours and Company, Wilmington, Del., a corporation of DelawareFiled Apr. 10, 1961, Ser. No. 101,747

2 Claims. (Cl. 11850) This invention relates to a new process andapparatus for applying liquid finish to a continuously movingfilamentary tow. More particularly, the invention relates to a processand apparatus for uniformly applying liquid finish to a very largenumber of continuous filaments comprising a tow.

To effectively process textile fibers into yarns and other more finishedproducts, it is necessary to apply a surface lubricant or other liquidconditioning agent to the fibers. Moreover, it is essential that theconditioning agent be present in an essentially uniform amount onsubstantially all the fibers undergoing textile processing. The mosteconomically feasible way to apply such finish to the fibers is whilethey are in the form of a very large tow of many tens of thousands ofcontinuous filaments as collected from the spinning machine. When thefinish ingredients are applied to a washed and drawn tow of, forexample, acrylonitrile polymer filaments while still wet, there issubstantial finish migration during drying and many filaments acquire agreat excess of finish while many others retain very little, if any,finish at all. Obviously, application of finish to the dried filamentsobviates this migration problem; but to apply the conditioning agent tothe very large number of dry filaments in a single bundle or tow withany semblance of uniformity of application to all the filaments hasproved to be a serious problem.

It is, therefore, an object of the present invention to provide anapparatus for applying a liquid finish to a dense, filamentary tow.Another object of the invention is to provide an apparatus for applyinga liquid finish to a moving tow in a predetermined amount uniformly toeach of the filaments comprising the tow. It is another object of theinvention to provide a process for applying a uniform liquid finish tothe filaments of a dense, filamentary tow. These and other objects willbecome apparent from the following detailed description and accompanyingdrawings, in which:

FIGURE 1 is a cross-sectional view of the apparatus of the inventiontaken along a line parallel to the direction of travel of thefilamentary tow;

FIGURE 2 is an offset cross-sectional view of the apparatus taken alongline 22 of FIGURE 1; and

FIGURE 3 is a perspective view of a portion of the finish applicatornozzle shown in FIGURE 1.

Referring now to FIG. 1, the apparatus of this invention comprises arigid, essentially airtight, compartmented housing 10, having two finishapplication chambers 12 and 14 with nozzles 16 and 18 mounted therein,and two exhaust chambers 20 and 22 positioned opposite chambers 12 and14, respectively, on either side of the path of travel of a filamentarytow 11.

The filamentary tow 11 is fed into the housing through an inlet 24located between tow supporting members 26 and 28 and is guided throughthe housing by sup porting members 30, 32, 34, and 36. The tow isdischarged from the housing through outlet 38 between tow supportingmembers 40 and 42. Support members 26 and 42 are secured to chamberaccess covers 44 and 46, respectively, which are in turn hingeablymounted on supports 45 and 47. Accordingly support member 26 may bemoved toward and away from support member 28 to substantially seal inlet24 and to accommodate different 3,172,780 Patented Mar. 9, 1965thicknesses of tow passing through housing 10. Likewise support member42 may be moved toward and away from support member 40.

In the course of travel of the tow 11 through the housing, a sheet offluid, which is discharged from orifice 48 of nozzle 16, is directedonto one of the major surfaces of the tow at a position between supportmembers 28 and 30. As illustrated in FIG. 2, nozzle 16 is elongated andextends across the tow 11 at right angles to its direction of travel,thus providing a sheet of fluid which extends across the full width ofthe major surface of the tow. Referring again to FIG. 1, simultaneouslywith the application of the fluid, a negative pressure from exhaustchamber 20 is exerted on the opposite side of the tow in a zone betweensupport members 28 and 32.

As the tow 11 continues to travel through housing 10, a sheet of fluiddischarged from nozzle 18 is applied to the opposite surface of the towat a position between supporting members 36 and 40. Simultaneously, anegative pressure is exerted on the other side of the tow by exhaustchamber 22 in the zone between supporting members 34 and 40.

Referring now to FIGS. 1 and 2, duct 50 is positioned to withdraw airfrom exhaust chamber 20 which extends across the width of tow 11. Asimilar duct 52 withdraws air from exhaust chamber 22. The ducts may beconnected to separate or a common exhaust system.

The nozzles will now be described in more detail. Referring again toFIGS. 1 and 3, nozzle 16 is provided with an air supply reservoir 54which is in communication through channel 56 with lips 58 and 59 whichform orifice 48. A gaseous medium, under pressure, is supplied to theair reservoir 54 through conduit 64. Liquid finish supplied to a liquidreservoir 62 through conduit 66 intermingles with the gaseous medium atthe juncture of channel 56 and lips 58 and 59 and is discharged throughorifice 48 in the form of a sheet of atomized fluid.

Nozzle 18 is also provided with an air supply reservoir 68, a liquidsupply reservoir 70, and conduits 72 and 74 for supplying air and liquidto the respective reservoirs. The fluid mixture provided byintermingling of air supplied through channel 76 is discharged fromorifice 78 and directed onto tow 11 at a position intermediatesupporting members 36 and 40.

In the fabrication of the nozzles 16 and 18, a number of parts may beutilized for ease of assembly and disassembly for cleaning. These partsmay be joined together by conventional means, with sealing gaskets 80and 82, as illustrated in FIG. 3, being utilized to provide a seal anddefine the Width of channel 56 and orifice 48.

In the fabrication of the apparatus of the present inve 1* tion, allparts coming in contact with the moving tow should be of material whichresists abrasion but, at the same time, does not damage the filaments ofthe tow. For example, the supporting members 26, 28, 30, 32, 34, 36, 40,and 42 may be coated with a synthetic resin such aspolytetrafluoroethylene which resists abrasion and coincidentallyprovides lubricity.

In carrying out the process of this invention, a dense tow, in the formof a web of substantially uniform thicl ness, comprising from about50,000 to 250,000 filaments or more of textile denier, is passed throughthe liquid finish apparatus at a predetermined rate. As the tow ispassed into the essentially airtight housing, a sheet of fluid underpressure is directed onto the surface of the tow at a right angle to itsdirection of travel at a localized position. Simultaneously, a negativepressure is applied to the other surface of the tow in a zone adjacentto the localized position. Thereafter, at a position displaced from thefirst localized position, a second sheet of fluid, under pressure, isdirected onto the other surface of the tow while a negative pressure isapplied to the opposite surface of the tow.

Upon examination of the tow, it is found that each of the filaments iscoated with a substantially uniform quantity of the liquid material.

The amount of liquid applied to the tow and the pressure used will, ofcourse, depend on the particular liquid finish being used as well as thedensity of thetow. Gen erally, by the described process, relatively highspeeds, e.g., 75 to 1000 feet per minute, may be utilized withoutstanding uniformity of finish application being attained. The amountof negative pressure or vacuum must, of course, be adjusted, dependingon such factors as Viscosity of the material being utilized, thepressure and temperature at which it is applied, and the speed of traveland density of the tow. The pressure may be only slightlysubatrnospheric, e.g., one-half to two inches of water, negative gagepressure, or lower.

The principal advantage provided by the present invention resides in theapplication of uniform quantity of finish to the filaments throughout adense filamentary tow. In addition, this uniformity is achieved byspeeds somewhat in excess of those possible utilizing known apparatuswhich has proved to be unsatisfactory in obtaining uniformity ofapplication. The apparatus of this invention is likewise essentiallymaintenance-free since it is free of moving parts. In addition, theapparatus is exceptionally reliable without encountering difiicultiesdue to plugging and consequent non-uniformity of finish applicationprovided the finish contains no insoluble particles. i

As many widely diiferent embodiments of this invention may be madewithout departing from the spirit and scope thereof, it is to beunderstood that this invention is not to be limited to the specificembodiments thereof except as defined in the appended claims.

We claim:

1. Apparatus for applying a liquid finish to a moving dense filamentarytow of substantially uniform thickness and having two essentially smoothopposed major surfaces, said apparatus comprising in combination a rigidessentially airtight housing having an elongated inlet for receivingsaid tow and an elongated outlet for discharging said tow from saidhousing, a plurality of supporting members mounted in said housing forguiding said tow therethrough, said inlet and said outlet -each beingformed by two supporting members; 'the first of said two'members beingfixedly attached to said housing andthe other being hingeably mountedfor movement toward and away from said first member to substantiallyseal said housingass'aid tow movestherebetween, two nozzles each havinga pair of lips defining an elongated discharge orifice for directing asheet of fluid onto said tow at a localized position mounted in saidhousing on opposite sides of said tow, each nozzle being spaced "fromone of said major surfaces of said tow with said discharge orificeextending across said tow at a right angle to its direction of travel,and exhaust means opposite each nozzle for applying a negative pressureto said tow in a zone opposite said localized position.

2. The apparatus of claim 1 wherein the lips of said nozzles are incommunication with a liquid reservoir and a compressed air reservoir toprovide a sheet of atomized fluid.

References Cited in the file of this patent UNITED STATES PATENTS1,667,408 Allen Apr. 24', 1928 2,963,002 Glaus Dec. 6, 1 960 FOREIGNPATENTS 556,207 Belgium Apr. 15, 1957

1. APPARATUS FOR APPLYING A LIQUID FINISH TO A MOVING DENSE FILAMENTARYTOW OF SUBSTANTIALLY UNIFORM THICKNESS AND HAVING TWO ESSENTIALLY SMOOTHOPPOSED MAJOR SURFACES, SAID APPARATUS IN COMBINATION A RIGIDESSENTIALLY AIRTIGHT HOUSING HAVING AN ELONGATED INLET FOR RECEIVINGSAID TWO AND AN ELONGATED OUTLET FOR DISCHARGING SAID TOW FROM SAIDHOUSING, A PLURALITY OF SUPPORTING MEMBERS MOUNTED IN SAID HOUSING FORGUIDING SAID TOW THERETHROUGH, SAID INLET AND SAID OUTLET EACH BEINGFORMED BY TWO SUPPORTING MEMBERS, THE FIRST OF SAID TWO MEMBERS BEINGFIXEDLY ATTACHED TO SAID HOUSING AND THE OTHER BEING HINGEABLY MOUNTEDFOR MOVEMENT TOWARD AND AWAY FROM SAID FIRST MEMBER TO SUBSTANTIALLYSEAL SAID HOUSING AS SAID TOW MOVES THEREBETWEEN, TWO NOZZLES EACHHAVING A PAIR OF LIPS DEFINING AN ELONGATED DISCHARGE ORIFICE FORDIRECTING A SHEET OF FLUID ONTO SAID TOW AT A LOCALIZED POSITION MOUNTEDIN SAID HOUSING ON OPPOSITE SIDES OF SAID TOW, EACH NOZZLE BEING SPACEDFROM ONE OF SAID MAJOR SURFACES OF SAID TOW WITH SAID DISCHARGE ORIFICEEXTENDING ACROSS SAID TOW AT A RIGHT ANGLE TO ITS DIRECTION OF TRAVEL,AND EXHAUST MEANS OPPOSITE EACH NOZZLE FOR APPLYING A NEGATIVE PRESSURETO SAID TOW IN A ZONE OPPOSITE SAID LOCALIZED POSITION.